can server 2003 be added to sbs 2011 domain

Yes absolutely no reason why not :)

The limitation to SBS is you can't have additional DCs you can add as many member servers as you like

As a server - not a problem - as a Domain Controller - No.

http://technet.microsoft.com/en-us/library/cc771132(WS.10).aspx

Hmmm, not strictly  true I am afraid Mr Hardisty!

It depends on the functional level of the domain/forest, which by default I believe is not Native Windows 2008 ;)

It is Windows 2008 on the one I just installed - and I haven't touched it.

>>The limitation to SBS is you can't have additional DCs you can add as many member servers as you like

Sorry netflo, that's wrong, you can have as many DC's or Member Servers as you like but you cannot have more than one SBS server.

depends if it's a migration or not :)

If you migrate from SBS2003 to SBS2011 then you set the domain/forest functional levels to Windows 2003 Native and it's not a requirement to change this when the migration is finished.

However, yes if it's a completely fresh installation it should go in with Windows 2008 functional levels as default :)

Yeah - Yeah - Migration Man!  Trust you!

Before accepting, Just want to clarify something.
I realise that on versions prior to sbs2011 one could have as many domain controllers and additional servers as one wanted. however the advertising spiel for sbs2011 tends to point to having to purchase additional Premium Add on's for each server one wishes to add.
It is this point I want to clarify.
I never migrate, for SBS it appears to be half a dozen of one and six of the other so in the long run, I always start from fresh.
My 1st scenario for this is
Head office with one SBS 2011 Standard and one local Server 2003 and one remote Server 2003.
No SQL requirement therefore, at this time, no Premium add on is required. We already have the licenses for Server 2003. Is this scenario available to me?

No it is not available to you!

And yes, you can have as many domain controllers and additional servers as you like as long as you have the appropriate WIndows licenses for them.

In answer to your question, yes you can.

Good discussion. I suspect it will help others. My learning curve from this is
Local SBS 2011 Standard as MDC with local and remote servers of 2003 or above but if any of them are required to be DC's then they need to be of the same vintage as the SBS server.
I am still vague about wether I have to purchase the Premium add on to add a 2nd Server 2008 as a DC but I guess I will find out in due course.
Thank you for your help

You do not need the Premium Addon to add a second server/DC but it will save you paying full price for a license if that's what you do need.

The marketing of the product is confusing.
Essentials which we would probably never use due to lack of Exchange and user limit is USD $545
Standard which we will use is USD $1096.00
Premium Add on which does not advertise 2 Server Standard licenses, - only an additional one, plus an SQL 2008 R2 license is USD $1604

Server 2008 R2 is USD $1029.
Therefore
The cost of a full license for Server 2008 R2  is less than the cost of the premium add on ? - unless the Premium add-on has two Server 2008 R2 licenses like the SBS Premium 2008 used to have. But I have not seen any marketing information to confirm this!

SBS Standard is a single server unit.
SBS Premium includes an additional server license and SQL Server license, so you would have the SBS server and a second Windows 2008 Server.